1)Girl will call boy ask about homework, then subsequently go on
and ask wat u doing, where u now, and talk about 1001 things other
than HOMEWORK.
2)Notice girl keep on staring at u sometimes, or smile/grin for no
reason when you are with her.
3)Message u almost every single day, and send u messages such as
good nite, take care, friends forever bleah bleah bleah. If she
only like u as a fren, she wouldn't sms u everyday, or even
call.
4)Sometimes, when its time to go home, and yet she seems to be
finding excuses not to go home so soon so that she can go walk to
the bus-stop or train station with u.
5)Some people when they go out with the person they like, will fall
very very quiet in a rather big grp, but when with u alone or in a
small grp of 3-4 people, will be quite chatty. Or when walking in a
grp, somehow she always seemed to be walking next or near u, but
never away from u.
These are just some hints that I personally experience, not
necessary applies to all.